The present invention relates to a sheet post-processing device and an image processing apparatus, and more particularly, relates to a sheet post-processing device for performing a folding operation and a saddle stitching operation on sheets discharged from an image forming apparatus, and an image forming apparatus equipped with the sheet post-processing device.
Japanese Patent Publication No. 2000-72320 has disclosed a sheet post-processing device (finisher). The sheet post-processing device performs a saddle stitching operation on a plurality of sheets having an image recorded thereon and discharged from an image forming apparatus. The sheet post-processing device also folds the sheets along a stitched portion thereof to bind a booklet. The sheet post-processing device performs the saddle stitching operation and the folding operation while edges of the sheets are aligned. The booklet is finished with the edges of the sheets neatly aligned.
As an increasing number of handicapped and aged people are involved in social and corporate activities, a variety of efforts are made to provide an environment suitable for the handicapped and aged people in corporate offices, government offices and the likes.
However, the booklets bound by such a conventional sheet post-processing device are typically aligned at the edges thereof. Accordingly, while the booklets with the page edges neatly aligned look good, it is difficult to turn pages for people who are forced to use a single hand.
It is an object of the present invention to provide a sheet post-processing device for binding a booklet that is easy to turn pages, and an image forming apparatus equipped with such a sheet post-processing device.
Further objects and advantages of the invention will be apparent from the following description of the invention.
In the first aspect of the present invention, a sheet post-processing device includes a placement unit for placing sheets discharged from an image forming apparatus, an offset unit for successively offsetting an edge of each sheet on the placement unit, and a folding unit for folding a stack of the sheets with the edge of each sheet offset by the offset unit.
According to the first aspect of the present invention, the sheets discharged from the image forming apparatus are stacked on the placement unit with the edge of each sheet successively offset by the offset unit. The folding unit performs a folding operation on the stack of the sheets with the edge of each sheet offset. Since the folding unit performs the folding operation on the sheet stack in a state that the offset unit offsets the edge of each sheet successively, the pages of the sheet stack are easy to turn.
In the second aspect of the present invention, a sheet post-processing device includes a placement unit for placing sheets discharged from an image forming apparatus, an offset unit for successively offsetting an edge of each sheet on the placement unit, and a saddle stitching unit for saddle stitching a stack of the sheets with the edge of each sheet offset by the offset unit.
According to the second aspect of the present invention, the sheets discharged from the image forming apparatus are stacked on the placement unit with the edge of each sheet successively offset by the offset unit. The saddle stitching unit performs a saddle stitching operation on the sheet stack with the edge of each sheet offset. The saddle stitching unit performs the saddle stitching operation on the sheet stack in the state that the edge of each sheet is successively offset by the offset unit. Therefore, when the saddle stitched sheet stack is folded, the pages of the resulting booklet are easy to turn.
In the third aspect of the present invention, a sheet post-processing device includes a placement unit for placing sheets discharged from an image forming apparatus, an offset unit for successively offsetting an edge of each sheet on the placement unit, a saddle stitching unit for performing a saddle stitching operation on a stack of the sheets with the edge of each sheet offset by the offset unit, and a folding unit for performing a folding operation on a predetermined position of the stack of the sheets saddle stitched by the saddle stitching unit.
According to the third aspect of the present invention, the offset unit successively offsets the edge of each of the sheets discharged from the image forming apparatus, and the sheets are stacked on the placement unit. Then, the saddle stitching unit performs a saddle stitching operation on the sheet stack in the state that the offset unit successively offsets the edge of each sheet. The folding unit performs a folding operation on the predetermined position of the stack of the sheets saddle stitched by the saddle stitching unit. In the third aspect, the saddle stitching unit performs the saddle stitching operation on the sheet stack in the state that the offset unit offsets the edge of each sheet successively, and the folding unit performs the folding operation at the predetermined position of the stack of the sheets saddle stitched by the saddle stitching unit, thereby making it easy to turn pages of the booklet.
According to the first through third aspects, the offset unit preferably offsets the sheets stacked on the placement unit so that an edge portion of each sheet remains visible when viewed from above or from below the sheet. In this arrangement, all edges of the sheets are shifted with each other, and the pages of the sheet stack or the booklet are easy to turn. According to the second and third aspects, the saddle stitching unit preferably performs the saddle stitching operation on a position of the sheets closer to one edge opposite to the other edge. In this arrangement, the sheet stack is folded or is subjected to the folding operation, and the edges of all pages are offset with each other, thereby making it easy to turn the pages. In the first and third aspect, the folding unit preferably performs the folding operation so that an edge of the innermost sheet remains visible after the stack of the sheets is folded. Therefore, all pages of the sheet stack or booklet subsequent to the folding operation have the edges shifted with each other, thereby making it further easy to turn the pages. In the third aspect, the folding unit preferably performs the folding operation on the saddle stitched stack sheets at a saddle stitching position as a folding position.
In the fourth aspect of the present invention, a sheet post-processing device includes a placement unit for placing sheets discharged from an image forming apparatus; a restraining unit movable between a restraining position at which the restraining unit restrains and aligns edges of the sheets discharged into the placement unit and a retraction position to which the restraining unit is retracted from the restraining position thereof; an urging unit for urging the sheets discharged into the placement unit toward the restraining unit; a sheet moving unit movable between the first position at which the sheet moving unit moves all the sheets by a predetermined distance with all the sheets on the placement unit nipped and the second position at which the sheet moving unit is away from the sheets on the placement unit and allows the urging unit to urge the sheets; a folding unit for performing a folding operation on the sheets; and a control unit for controlling the restraining unit to move to the retraction position from the restraining position after restraining and aligning the edge of the sheet discharged into the placement unit, and for controlling the sheet moving unit to move all the sheets on the placement unit by the predetermined distance. Then, the control unit controls the urging unit to urge the sheets toward the restraining unit for alignment while the restraining unit and sheet moving unit move to the restraining position and the second position, respectively. The control unit repeats the above steps until a stack of the sheets with the edge of each sheet offset with each other is formed on the placement unit, and then controls the folding unit to perform the folding operation on the stack of the sheets.
In the fourth aspect of the present invention, with the control unit, the restraining unit moves to the retraction position from the restraining position after restraining and aligning the edges of the preceding sheets discharged into the placement unit. After the sheet moving unit at the first position thereof moves all the sheets on the placement unit by the predetermined distance, the restraining unit and sheet moving unit move to the restraining position and the second position, respectively. Under this state, the urging unit urges the subsequent sheets toward the restraining unit for alignment. The control unit repeats this series of operations, thereby forming the stack of the sheets with the edge of each sheet successively offset. The control unit controls the folding unit to perform the folding operation on the stack of the sheets. As a result, the folding operation is performed in the state that each sheet is offset with each other, thereby making it easy to turn the pages.
In the fifth aspect of the present invention, a sheet post-processing device includes a placement unit for placing sheets discharged from an image forming apparatus; a restraining unit movable between a restraining position at which the restraining unit restrains and aligns edges of the sheets discharged into the placement unit and a retraction position to which the restraining unit is retracted from the restraining position thereof; an urging unit for urging the sheets discharged into the placement unit toward the restraining unit; a sheet moving unit movable between the first position at which the sheet moving unit moves all the sheets by a predetermined distance with all the sheets on the placement unit nipped and the second position at which the sheet moving unit is away from the sheets on the placement unit and allows the urging unit to urge the sheets; a saddle stitching unit for performing a saddle stitching operation on the sheets; and a control unit for controlling the restraining unit to move to the retraction position from the restraining position after restraining and aligning the edges of the sheets discharged into the placement unit, and for controlling the sheet moving unit to move all the sheets on the placement unit by the predetermined distance. Then, the control unit controls the urging unit to urge the sheets toward the restraining unit for alignment while the restraining unit and sheet moving unit moved to the restraining position and the second position, respectively. The control unit repeats the above steps until a stack of the sheets with the edge of each sheet successively offset with each other is formed on the placement unit, and then controls the saddle stitching unit to perform the saddle stitching operation on the stack of the sheets. In the fifth aspect of the present invention, the stitching operation is performed in the state that the edge of each sheet is offset with each other. The sheet stack is folded after the saddle stitching operation, thereby making it easy to turn the pages.
In the sixth aspect of the present invention, a sheet post-processing device includes a placement unit for placing sheets discharged from an image forming apparatus; a restraining unit movable between a restraining position at which the restraining unit restrains and aligns edges of the sheets discharged into the placement unit and a retraction position to which the restraining unit is retracted from the restraining position thereof; an urging unit for urging the sheets discharged into the placement unit toward the restraining unit; a sheet moving unit movable between the first position at which the sheet moving unit moves all the sheets by a predetermined distance with all the sheets on the placement unit nipped and the second position at which the sheet moving unit is away from the sheets on the placement unit and allows the urging unit to urge the sheets; a saddle stitching unit for performing a saddle stitching operation on the sheets; and a control unit for controlling the restraining unit to move to the retraction position from the restraining position after restraining and aligning the edges of the sheets discharged into the placement unit, and for controlling the sheet moving unit to move all the sheets on the placement unit by the predetermined distance. Then, the control unit controls the urging unit to urge the sheets toward the restraining unit for alignment while the restraining unit and sheet moving unit moved to the restraining position and the second position, respectively. The control unit repeats the above steps until a stack of the sheets with the edge of each sheet successively offset with each other is formed on the placement unit. Then, the control unit controls the saddle stitching unit to perform the saddle stitching operation, and then controls the folding unit to perform the folding operation at the saddle stitched portion of the stack of the sheets saddle stitched by the saddle stitching unit. In the sixth aspect of the present invention, the stitching operation is performed with the edge of each sheet successively offset with each other, and the folding operation is performed on the sheet stack at the saddle stitch portion subsequent to the saddle stitching operation, thereby making it easy to turn the pages.
In the fourth through sixth aspects, the control unit preferably controls the restraining unit to hold all the sheets on the placement unit at the restraining position when the urging unit urges the subsequent sheets toward the restraining unit. When the urging unit urges the subsequent sheets toward the restraining position, the sheet moving unit is at the second position to allow the urging unit to urge the sheets, and all the sheets are free (not in a held state) on the placement unit. If the subsequent sheets are urged, a posture of the sheets with the edge of each sheet offset is destroyed. Therefore, the restraining unit holds all the sheets on the placement unit, so that the offset position of the sheets remains unchanged. Since the restraining unit holds the sheets without extra means for holding the sheets, it is possible to make the apparatus small. The sheet post-processing device may further include a setting unit for setting and adjusting a distance of travel of all the sheets to be moved by the sheet moving unit on the placement unit. The control unit controls the sheet moving unit in accordance with the distance of travel set and adjusted by the setting unit. With this configuration, the distance of travel, namely, the shift of each sheet is set and adjusted. Therefore, it is easy to turn the pages of the resulting booklet even for a person with large fingers, a person with a handicap in a hand, or a person with a difficulty in controlling shaking fingers.
In the seventh aspect of the present invention, an image forming apparatus includes a storage unit for storing sheets; a sheet feeder unit for feeding the sheets from the storage unit one by one; an image forming unit for forming an image on the sheet fed by the sheet feeder unit; a placement unit for placing the sheets with the image thereon discharged from the image forming unit; a restraining unit movable between a restraining position at which the restraining unit restrains and aligns edges of the sheets discharged into the placement unit and a retraction position to which the restraining unit is retracted from the restraining position thereof; an urging unit for urging the sheets discharged into the placement unit toward the restraining unit; a sheet moving unit movable between the first position at which the sheet moving unit moves all the sheets by a predetermined distance with all the sheets on the placement unit nipped and the second position at which the sheet moving unit is away from the sheets on the placement unit and allows the urging unit to urge the sheets; a folding unit for performing a folding operation on the sheets; and a control unit for controlling the restraining unit to move to the retraction position from the restraining position after restraining and aligning the edge of the sheet discharged into the placement unit, and for controlling the sheet moving unit to move all the sheets on the placement unit by the predetermined distance. Then, the control unit controls the urging unit to urge the sheets toward the restraining unit for alignment while the restraining unit and sheet moving unit move to the restraining position and the second position, respectively. The control unit repeats the above steps until a stack of the sheets with the edge of each sheet offset with each other is formed on the placement unit, and then controls the folding unit to perform the folding operation on the stack of the sheets.
In the eighth aspect of the present invention, an image forming apparatus includes a storage unit for storing sheets; a sheet feeder unit for feeding the sheets from the storage unit one by one; an image forming unit for forming an image on the sheet fed by the sheet feeder unit; a placement unit for placing the sheets with the image thereon discharged from the image forming unit; a restraining unit movable between a restraining position at which the restraining unit restrains and aligns edges of the sheets discharged into the placement unit and a retraction position to which the restraining unit is retracted from the restraining position thereof; an urging unit for urging the sheets discharged into the placement unit toward the restraining unit; a sheet moving unit movable between the first position at which the sheet moving unit moves all the sheets by a predetermined distance with all the sheets on the placement unit nipped and the second position at which the sheet moving unit is away from the sheets on the placement unit and allows the urging unit to urge the sheets; a saddle stitching unit for performing a saddle stitching operation on the sheets; and a control unit for controlling the restraining unit to move to the retraction position from the restraining position after restraining and aligning the edges of the sheets discharged into the placement unit, and for controlling the sheet moving unit to move all the sheets on the placement unit by the predetermined distance. Then, the control unit controls the urging unit to urge the sheets toward the restraining unit for alignment while the restraining unit and sheet moving unit moved to the restraining position and the second position, respectively. The control unit repeats the above steps until a stack of the sheets with the edge of each sheet successively offset with each other is formed on the placement unit, and then controls the saddle stitching unit to perform the saddle stitching operation on the stack of the sheets. In the fifth aspect of the present invention, the stitching operation is performed in the state that the edge of each sheet is offset with each other. The sheet stack is folded after the saddle stitching operation, thereby making it easy to turn the pages.
In the ninth aspect of the present invention, an image forming apparatus includes a storage unit for storing sheets; a sheet feeder unit for feeding the sheets from the storage unit one by one; an image forming unit for forming an image on the sheet fed by the sheet feeder unit; a placement unit for placing the sheets with the image thereon discharged from the image forming unit; a restraining unit movable between a restraining position at which the restraining unit restrains and aligns edges of the sheets discharged into the placement unit and a retraction position to which the restraining unit is retracted from the restraining position thereof; an urging unit for urging the sheets discharged into the placement unit toward the restraining unit; a sheet moving unit movable between the first position at which the sheet moving unit moves all the sheets by a predetermined distance with all the sheets on the placement unit nipped and the second position at which the sheet moving unit is away from the sheets on the placement unit and allows the urging unit to urge the sheets; a saddle stitching unit for performing a saddle stitching operation on the sheets; and a control unit for controlling the restraining unit to move to the retraction position from the restraining position after restraining and aligning the edges of the sheets discharged into the placement unit, and for controlling the sheet moving unit to move all the sheets on the placement unit by the predetermined distance. Then, the control unit controls the urging unit to urge the sheets toward the restraining unit for alignment while the restraining unit and sheet moving unit moved to the restraining position and the second position, respectively. The control unit repeats the above steps until a stack of the sheets with the edge of each sheet successively offset with each other is formed on the placement unit. Then, the control unit controls the saddle stitching unit to perform the saddle stitching operation, and then controls the folding unit to perform the folding operation at the saddle stitched portion of the stack of the sheets saddle stitched by the saddle stitching unit.